Suc-LLVY-D-Aminoluciferin

Suc-LLVY-D-Aminolucifin is a sentive luminogenic substrate for 20S proteasome, calpains and other chymotrypsin-like proteases. Upon the protease-induced hydrolysis the non-luminescent substrate generates the luminescent D-aminoluciferin that can be easily detected with luciferase-induced luminescence. This aminoluciferin substrate is much more sensitive than the chromogenic and fluorogenic substrates. The most common form of the proteasome is known as the 26S proteasome that contains one 20S core particle structure and two 19S regulatory caps. All 20S particles consist of four stacked heptameric ring structures that are themselves composed of two different types of subunits, alpha subunits are structural in nature, whereas beta subunits are predominantly catalytic. The outer two rings in the stack consist of seven alpha subunits each, which serve as docking domains for the regulatory particles and the alpha subunits N-termini form a gate that blocks unregulated access of substrates to the interior cavity. The inner two rings each consist of seven beta subunits and contain the protease active sites that perform the proteolysis reactions.